Controlled Temporary Mobile Network

ABSTRACT

A communication device and method for controlling a temporary Mobile Group within a Controlled Temporary Mobile Network. The device is configurable by an administrator to act as a Mobile Group Node within the temporary Mobile Group. The administrator may further configure the device to act as a Mobile Group Leader, which manages and controls the temporary Mobile Group according to an adaptable policy engine.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a mobile node within a ControlledTemporary Mobile Network, which is an improved mobile temporary networkdivided into mobile groups, the mobile nodes being e.g. portablecomputer terminals.

BACKGROUND OF THE INVENTION

The wireless network technology is developing rapidly, accompanied by anincreasing use of wireless networks, while the Internet is evolvingtowards a more wireless environment. A wireless network of mobile nodes,being e.g. portable personal computers or PDA:s (Personal DigitalAssistants), is capable of providing communication between the nodes, aswell as between each node and other external networks, such as theInternet, e.g. by means of e-mail messages. A LAN (Local Area Network)and a PAN (Personal Area Network) are examples of networking schemesenabling computing devices, such as e.g. personal computers, printers orPDAs, to communicate wirelessly (or by wire) with each other over shortdistances. E-mail communication may be performed by means of a computerterminal having a wireless (and/or wired) connection to the Internet, aswell as by means of a cellular telephone connected to the Internet via aradio access network.

Some wireless networks, e.g. the cellular GSM (Global System for Mobilecommunication) and UMTS (Universal Mobile Telecommunication System),require an existing infrastructure, while a mobile (temporary) ad-hocnetwork, such as e.g. a MANET (Mobile Ad-hoc NETwork), according to theMANET working group of the IETF (Internet Engineering Task Force), donot require any fixed infrastructure. The mobile nodes of a MANET areallowed to join and leave the network spontaneously and dynamically,depending on their movement and wish to communicate. The routingprotocols for a MANET include e.g. AODV (Ad-hoc On-demand DistanceVector) and DSR (Dynamic Source Routing), and these protocols areadapted to the frequent changes of the network topology in a temporaryad-hoc network. However, both AODV and DSR assumes the existence of onlyone MANET, and if a new mobile node appear within the range, the newnode will automatically become a part of the existing network, therebyforming a larger, extended network. The nodes of a MANET may be dividedinto groups or clusters, and routing protocols for clusters of a MANETinclude Cluster Based Routing Protocol (CBRP), Cluster-Head GatewaySwitching Routing Protocol (CGSR) and Zone-Based Hierarchical Link StateProtocol (ZHLS). Prior art relating to MANETs, that may be divided intoclusters, is disclosed in e.g. the patent documents no. WO 03/094026, US2004/010476, US 2005/0063313 and US 2005/0041627. Prior art relating tofixed networks, configured by an administrator to be static, and whichare controlled by a policy engine, are disclosed e.g. in US 2003/0154404and US 2005/0060537. A policy engine is a set of policy rules comprisingexecutable instructions used by a computing device to control theoperation, the policy rules determining how the device responds to theoccurrence of specific events.

However, the communication within a temporary, spontaneous network suchas e.g. a MANET is normally not controlled, and every node within rangeof the network will be allowed to join. Consequently, a MANET involvesseveral drawbacks, such as e.g. the lack of security due to the factthat the mobile nodes of a MANET normally have access to all theinformation within the network, and that any mobile node is allowed tojoin the MANET spontaneously, without any clearance or control. It isnot always desirable that two wireless networks merge into one, enlargednetwork, or that every mobile node that comes into range is included inthe network and allowed to share all network resources, without anylimitations. A wireless network may not want to reveal its internaltopology, including addresses to the internal infrastructure and to thevarious functionalities of the network, to any mobile node or otherwireless network that comes into range. Further, when every mobile nodecoming into range is allowed to join, as in a MANET, the number ofmobile nodes may be large, and the routing may eventually occupy allavailable bandwidth.

Therefore, the aim of the present invention is to alleviate the problemsdescribed above, regarding how to control the mobile nodes joining atemporary mobile network and limit the number of nodes, as well as howto control the communication and routing within the network and theaccess to network resources and information.

DESCRIPTION OF THE INVENTION

Thus, it is an object of the present invention to provide an improvedtemporary mobile network comprising one or more mobile nodes, requiringnegotiations before allowing new nodes to join the network and beforesharing information and resources available through the network, as wellas regarding routing through the network.

These and other objects are achieved in a communication device providedwith a Controlled Temporary Mobile Group functionality, and of themethod in a communication device provided with a Controlled TemporaryMobile Group functionality, according to the attached claims.

The claims relate to a communication device provided with a ControlledTemporary Mobile Network-functionality, which is configurable by anadministrator to enable the device to act as a Mobile Group Node in atemporary Mobile Group within a Controlled Temporary Mobile Network(CTMNET). The temporary Mobile Group comprises one or more Mobile GroupNodes, and one of said Mobile Group Nodes acts as a Mobile Group Leader.The Controlled Temporary Mobile Network-functionality comprises anadaptable policy engine, which is settable by an administrator, and theControlled Temporary Mobile Network-functionality is staticallyconfigurable by an administrator to enable the device to act as a MobileGroup Leader. A Mobile Group Leader is arranged to control the joiningof other Mobile Group Nodes in the temporary Mobile Group according tosaid adaptable policy engine.

An administrator may be e.g. a user, a system operator, IT-support, avendor, or an administrator.

A communication device acting as a Mobile Group Leader may further bearranged to control the access to information resources in the temporaryMobile Group according to said adaptable policy engine, and/or tocontrol the routing within a temporary Mobile Group between a sourcenode and a destination node according to said adaptable policy engine.The routing may use the prefix of the IP-address of the destinationnode.

The Controlled Temporary Mobile Network-functionality may beconfigurable by an administrator to disable the communication device toact as a Mobile Group Leader.

The Controlled Temporary Mobile Network-functionality may be dynamicallyconfigurable by a communication device acting as Mobile Group Leader toenable any device within a temporary Mobile Group to act as a MobileGroup Gateway for communicating with another temporary Mobile Group.

The adaptable policy engine may comprise one or more policy rules thatare settable by an administrator, and one or more default policy rules.

The adaptable policy engine of a device acting as a Mobile Group Nodemay comprise policy rules associated with said Mobile Group Node.

The claims further relate to a method in a communication device providedwith a Controlled Temporary Mobile Network-functionality configured byan administrator to enable the device to act as a Mobile Group Leader ofa temporary Mobile Group within a Controlled Temporary Mobile Network,said method relating to the joining of a new Mobile Group Node in thetemporary Mobile Group, the communication device acting as Mobile GroupLeader performing the following steps:

-   -   Receiving a membership requesting message from a Mobile Group        Node;    -   Consulting its adaptable policy engine;    -   Receiving information from its policy engine that membership is        allowed;    -   Sending a reply to the Mobile Group Node to establish the        membership.

The communication device acting as a Mobile Group Leader may control theaccess to information resources within the temporary Mobile Group byconsulting its adaptable policy engine.

The communication device acting as a Mobile Group Leader may furtherappoint a Mobile Group Gateway within the temporary Mobile Group forcommunicating with another Mobile Group, by the following steps:

-   -   Receiving a message from another Mobile Group Node in the Mobile        Group requesting permission to communicate with another        temporary Mobile Group;    -   Consulting its policy engine;    -   Receiving information from its policy engine that communication        is allowed;    -   Dynamically configuring the Controlled Temporary Mobile Network        functionality of said another Mobile Group Node to act as a        Mobile Group Gateway.

A communication device acting as Mobile Group Leader may further performrouting from a source node within the temporary Mobile Group to adestination node in another temporary Mobile Group by the followingsteps:

-   -   Receiving a routing requesting message from the source node via        a Mobile Group Gateway of said temporary Mobile Group;    -   Consulting its adaptable policy engine;    -   Sending a routing allowing message to the Mobile Group Gateway        of said temporary Mobile Group, allowing forwarding of the        routing requesting message according to its adaptable policy        engine to a Mobile Group Gateway of said another temporary        Mobile Group.

A communication device acting as Mobile Group Leader in a transitingtemporary Mobile Group may further perform a transit routing from asource node within another, first temporary Mobile Group to adestination node in another second, temporary Mobile Group, by thefollowing steps:

-   -   Receiving a routing requesting message from a Mobile Group        Gateway of said first temporary Mobile Group, via a Mobile Group        Gateway of said transiting temporary Mobile Group;    -   Consulting its adaptable policy engine;    -   Sending a routing allowing message to the Mobile Group Gateway        of said transiting temporary Mobile Group, allowing forwarding        of the routing requesting message according to its adaptable        policy engine to a Mobile Group Gateway of said second temporary        Mobile Group.

The routing may use the prefix of the IP-address of the destinationnode.

A communication device according may be reconfigured by an administratorto resign as a Mobile Group Leader.

Other features and further advantages of the invention will be apparentfrom the following description and figures, as well as from the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described in more detail and withreference to the embodiments and to the drawings of FIGS. 1-5, of which:

FIG. 1 schematically illustrates a Controlled Temporary Mobile Networkcomprising four temporary Mobile Groups,

FIG. 2 is a signalling diagram illustrating the signalling when a MobileGroup Node joins a temporary Mobile Group,

FIG. 3 illustrates a Controlled Temporary Mobile Network comprisingthree temporary Mobile Groups,

FIG. 4 is a signalling diagram illustrating the signalling when a routeis set up between two Mobile Group Nodes located in separate temporaryMobile Groups, and

FIG. 5 is a block diagram illustrating a communication device, providedwith a Controlled Temporary Mobile Network-functionality.

DESCRIPTION OF PREFERRED EMBODIMENTS

The terms and expressions used in the description and in the claims aremeant to have the meaning normally used by a person skilled in the art,and the following abbreviations and definitions are used:

CTMNET=Controlled Temporary Mobile Network, comprises one or moretemporary Mobile GroupsMG=Mobile Group, comprises one or more Mobile Group NodesMGN=Mobile Group Node, a node in an MG.MGL=Mobile Group Leader, a managing node in an MG.MGG=Mobile Group Gateway, a node in an MG communicating with an MGG in adifferent MG.GGR=Group Gateway Request, a message the MGG sends to the MGL toadvertise a newly found MGIRE=Inter-group Routing Error, a message the MGG sends to the MGL tonotify the MGL that the contact with an MG is lost.IG-RREQ=Inter-group Routing Request, a routing request within an MG.IG-RREQ-ALLOWED=Inter-group Routing Request Allowed, a message from theMGL to tell the MGG that an MGN is allowed to contact other MG.IG-RREP=Inter-group Routing Reply, a message sent between MGGs as ananswer to the IG-RREQ.

This invention comprises a mobile communication device, such as e.g. aportable personal computer, a PDA or a cellular mobile phone, providedwith a new Controlled Temporary Mobile Network (CTMNET)-functionality,configurable to enable the communication device to act as a Mobile GroupNode (MGN) in a temporary Mobile Group within a Controlled TemporaryMobile Network, and controlled by an adaptable policy engine. A MobileGroup (MG) according to this invention is a temporary Mobile Groupcomprising one or more Mobile Group Nodes. One of the Mobile Group Nodesis statically configured by an administrator, by means of a commandoption or a configuration interface, to manage and control the group byacting as a Mobile Group Leader (MGL) within said Mobile Group. Theadministrator is hereinafter defined to be any administrator of thecommunication device, e.g. an administrator, a user, a system operator,IT-support, or a vendor. According to an exemplary embodiment, theconfiguration of a Mobile Group Node is indirectly performed by theadministrator by means of a technical arrangement triggered by asuitable event.

A communication device configured to act as a Mobile Group Leader willact as an MGL statically, i.e. until the administrator re-configures thedevice to resign as an MGL. During a policy engine configuration, theMGL will store a set of rules for the Mobile Group in its adaptablepolicy engine, and the rules are settable by the administrator, e.g. tobe suitable for a particular environment of a Mobile Group, such as e.g.a confidential business meeting, or a completely or partly open meetingbetween colleagues or friends. The maximum number of Mobile Group Nodesin a temporary Mobile Group is preferably controlled by the policyengine, and may be settable by the Administrator. The acceptable size ofa particular temporary Mobile Group may also depend on the load andcapacity of the network. However, a suitable size for a temporary MobileGroup according to this invention is normally less than twenty MobileNodes, and a larger number of Mobile Nodes may result in the formationof additional temporary Mobile Groups within the CTMNET.

In order to facilitate the communication between MGNs located indifferent MGs, one or more MGNs in an MG is preferably configured by theMGL to act as a Mobile Group Gateway, MGG, which is allowed tocommunicate with MGGs located in another MG. Optionally, the MGL may actas an MGG, according to the policy engine. Thus, a Controlled TemporaryMobile Group functionality according to this invention is capable ofenabling a communication device to act as a Mobile Group Node, a MobileGroup Leader and a Mobile Group Gateway.

A temporary Mobile Group (MG) of a Controlled Temporary Mobile Network(CTMNET) according to this invention comprises a limited number ofMobile Group Nodes (MGN), i.e. communication devices beingwireless-enabled transceiver devices, running a TCP/IP-based networkprotocol stack with a new Temporary Mobile Group Routing Protocol(TMGRP), allowing multi-hop communication, while each device may roamspontaneously. A Controlled Temporary Mobile Network (CTMNET) accordingto this invention differs from prior art mobile and temporary ad-hocnetwork, e.g. a MANET, by having one statically assigned managementnode, i.e. the above described Mobile Group Leader MGL, and in that thenodes (MGNs) are not allowed to join a temporary Mobile Groupautomatically and spontaneously, as in the MANET model, but instead thejoining is controlled by the MGL, according to the rules in theadaptable policy engine. The joining of a new Mobile Group Node in atemporary Mobile Group is controlled according to predefined andsettable policy rules in a policy engine configured in the MGL, thesettable and/or selectable policy rules implementing an adaptable policyengine. A Controlled Temporary Mobile Network according to thisinvention allows borders to exist between different Mobile Groups, whilethe Mobile Group Nodes are able to communicate across a border in acontrolled fashion.

The adaptable policy engine comprises a set of predefined rules, whichare a suitable combination of default rules and rules that areselectable and settable by an administrator for the control andmanagement of a Mobile Group, as well as for the communication within anMG (intra-group communication), between different MGs (inter-groupcommunication), as well as transiting communication, by imposing rulesof node connectivity and of the propagation of network topologyinformation within the network.

Thus, a temporary Mobile Group according to this invention consists ofone or more Mobile Group Nodes (MGN), one Mobile Group Leader (MGL) andoptionally one or more Mobile Group Gateways (MGG). Any MGN has thefunctionality to act as an MGL or an MGG, if properly configured, andthe MGNs, MGLs and MGGs have unique node names. One embodiment of thenew Temporary Mobile Group Routing Protocol (TMGRP) used by an MGaccording to this invention is implemented by an addition of standardAODV extensions to the AODV messages RREQ, RREP, RRER.

FIG. 1 illustrates a Controlled Temporary Mobile Network 1 comprisingfour Mobile Groups, 10, 12, 14, 16, according to this invention, andMobile Group Nodes located in separate Mobile Groups communicate witheach other via Mobile Group Gateways 104, 124 a,b, 142, 164 (MGGs)located on the border between two Mobile Groups. Each Mobile Group Nodeillustrated in the figure consists of a communication device, such ase.g. a portable personal computer or a PDA, provided with a ControlledTemporary Mobile Network functionality configured to enable thecommunication device to act as a Mobile Group Node according to thisinvention. The Controlled Temporary Mobile Network functionality is notindicated in the figure, but is easily implemented by a person skilledin the art, and is not described in detail.

The first Mobile Group, 10, comprises three mobile nodes, of which oneis statically configured by an administrator to act as a Mobile GroupLeader, MGL, 102, one is dynamically appointed by the MGL to act asMobile Group Gateway, MGG, 104, and one mobile node constitutes a MobileGroup Node, MGN. 106. The second Mobile Group, 12, comprises five mobilenodes, of which one is statically configured by an administrator to actas a Mobile Group Leader, MGL, 122, two are dynamically appointed by theMGL to act as Mobile Group Gateways, MGGs, 124 a,b, and two mobile nodesconstitute ordinary Mobile Group Nodes, MGN, 127, 128. The third MobileGroup, 14, comprises only one mobile node, 142, which is staticallyconfigured by an administrator to act as a Mobile Group Leader, MGL, andwill simultaneously act as a Mobile Group Gateway, MGG. The fourthMobile Group, 16, comprises two mobile nodes, of which one is staticallyconfigured by an administrator to act as a Mobile Group Leader, MGL,162, while the other is dynamically appointed by the MGL to act as aMobile Group Gateway, MGG, 164.

A temporary Mobile Group 10, 12, 14, 16, according to this invention iscapable of intra-group wireless routing, which is the possibility offinding single-, or multiple hop routes between communication deviceswithin a temporary Mobile Group, and the possibility of advertisingservices (such as gateways) and controlling, granting and revokingrights to communicating devices regarding the access to the temporaryMobile Group, in accordance with the rules in the policy engine in theMobile Group Leader 102, 122, 142, 162, of each temporary Mobile Group.

Two temporary Mobile Groups according to this invention are also capableof inter-group wireless routing, which is concerned with finding routesto a destination located in a second Mobile Group, outside a firstMobile Group, and the inter-group wireless routing is handled accordingto the policy rules stored in the adaptable policy engines in the MGLsof said first and the second Mobile Groups.

A temporary Mobile Group according to this invention is also capable oftransit routing, which takes place when neither the source node nor thedestination node of a conversation is located in the temporary MobileGroup, but the temporary Mobile Group acts as an intermediate networkgroup. During transit routing, a temporary Mobile Group may want tolimit the exposure of its network topology and select the gateways forthe transiting, and by providing explicit transiting policies in thepolicy engine of a Mobile Group Leader of a temporary Mobile Group, itis possible to control the specific route of all transiting traffic.

Each MG 10, 12, 14, 16, in this figure has an MGL 102, 122, 142, 162,managing and controlling every MGN of the MG, and the MGL is serving theMGNs regarding membership requests and request for communication withanother MGN. Further, the MGL serves the MGGs 104, 124, 144, regardingmembership request, request for communication with another MGN andnotification of the discovery of new MG.

An MGL is statically assigned to act as an MGL by an administrator, bye.g. a command option or configuration interface, and the MGL willconsult its policy engine for every message the MGL receives. Theadaptable policy engine comprises a set of rules describing the policiesto apply for a certain request, and according to an exemplary embodimenta policy engine comprises a number of default rules. Further, the rulesof the policy engine may be deleted and altered, and new rules may beadded by the administrator in order to provide a suitable policy enginefor a particular environment of a Mobile Group. Examples of policy rulesof the policy engine are whether an MGN is allowed to contact anotherMGN, whether an MGG should receive traffic from a newly discovered MG,which MGN that is allowed to join a MG, the access to informationresources within the MG, and which nodes to use in a transit scenario.

According to a preferred embodiment of this invention, an MGLperiodically broadcasts a group advertisement, containing group ID and aflag indicating that it acts as MGL for the temporary Mobile Group, andmaintains the temporary Mobile Group by communicating with the MGNsindicated as members in the group. The MGN of an MG periodicallybroadcasts a node advertisement, containing the unique name of the MGNand the group ID. Further, the MGL manages the communication bysupplying routes to the MGNs located in other MGs via one or severalMGGs. When an MGN becomes member of an MG, the MGL stores the uniquename of the MGN, together with the IP address. Thereby, the MGL will beable to identify the members of the MG, and which policy rules to checkwhen asking for resources within this MG. AN MGN will timeout and bedeleted as member of the MG if the MGL does not receive any membershipupdate from the MGN within a predefined time interval.

Optionally, according to one exemplary embodiment of this invention, theMGL provides a dynamic configuration of an MGN becoming a member of theMG by sending an IP address, net mask and broadcast address to the MGNin a reply (e.g. a RREP) to the request for membership (e.g. a RREQ).

According to an exemplary embodiment of this invention, the policyengine of a Mobile Group Node is configurable by means of a public API(Application Programming Interface), and the administrator is able toregister selected call-back functions in the API for specific eventsduring the policy engine-configuration of an MGL. The administrator isable to control the policy rules for an MGN connecting to the MG bymeans of predefined events, and is also able to create new events andselect policy rules for the new events, to be stored in the policyengine of the MGL. The policy rules regarding a specific MGN is alsostored in the MGN itself.

A public API normally comprises the following functions:

-   -   MG_init_policy_engine—initiates registering of events and        callbacks.    -   MG_register_event—the event registering function.    -   MG_send_membership_request—requesting membership.    -   MG_send_welcome—welcoming an MGN into this MG.    -   MG_becomes_member—a welcome is received by the MGN becoming a        member of the MG    -   MG_drop_membership—leaving an MG    -   MG_send_message—sending a message to an MGN

Examples of predefined events in a policy engine for a temporary MobileGroup, according one exemplary embodiment of this invention are:

-   -   EVENT_NEW_MG_FOUND—A new MG is found    -   EVENT_LOST_MG—The MG, in which this MG is a member, has        disappeared    -   EVENT_MEMBERSHIP_REQUEST—A membership request message is        received    -   EVENT_WELCOME_RECEIVED—A welcome message is received    -   EVENT_MESSAGE RECEIVED—A message is received

The policy engine comprises a set of rules indicating the predefinedhandling of events, and the policy engine is adaptable by settable orselectable policy rules of the policy engine, thereby adapting aspecific temporary Mobile Group to a particular environment, e.g.regarding the security. A Mobile Group Leader comprises policy rules forthe management of the entire temporary Mobile Group, while the MobileGroup Nodes comprises the policy rules relating to itself. Examples ofthe predefined handling of events according to one exemplary embodimentof this invention are:

-   -   When an MGN discovers a new MG, and the MGN is not member of any        MG, the MGN will request membership in the MG.    -   An MGN requesting membership will default be accepted as a        member    -   When an MGN loses contact with an MG, the MGN will leave the MG.    -   When an MGG in a first MG discovers a second MG, the MGG will        report this to the MGL of the first MG.    -   When an MGL of a first MG receives a report from an MGG        indicating a second MG, the MGL will accept to receive data from        the second MG.

However, an important advantage with this invention is the adaptablepolicy engine, capable of adapting a temporary Mobile Group for anyparticular environment. An administrator may select specific policyrules, according to e.g. the security requirements of a temporary MobileGroup, and the above-described handling of events are only examples ofevent handling according to this invention.

FIG. 2 is a signalling diagram illustrating an example of the signallingbetween a Mobile Group Leader 102 and a Mobile Group Node 106 during aMobile Group Leader discovery, when the MGN 106 wants to join atemporary Mobile Group managed by the MGL 102. In step 210, the MGNreceives a broadcast message containing a group ID, and in step 215, theMGN requests membership to the MG by sending a request (RREQ) to theMGL.

(Actually, the MGN sends the request to the other MGN that the broadcastmessage was received from, and if this other MGN is not MGL, the requestis forwarded to the MGL by the MGN). In step 220, the MGL consults itspolicy engine 103 regarding the connection of the MGN to the MG. In step225, the policy engine allows the MGN to join the MG. Finally, in step230, the MGL sends a reply (RREP) to the MGN, allowing the MGN to jointhe MG, submitting a new IP address.

According to a preferred embodiment, an MGN periodically sends out amembership update message to its MGL to notify the MGL that the MGN isstill member of this MG. Any node receiving and forwarding thismembership update message will attach its unique name to this in apiggyback fashion, to reduce data traffic within the MG. The MGL repliesto this membership update message and all MGN on the route back to theoriginating MGN will update its timer for next initiation of amembership update. When an MGN does not receive any reply to amembership update message from its MGL, the MGN will timeout and leavethe MG.

An MGN coming into range of another MGN, located in another MG, iscapable of applying to its MGL for the right to interface with the otherMG. The MGL will consult its policy engine, and the MGN will beappointed MGG by the MGL, if the policy engine in the MGL permits this,and the new MGG will act as a border router for all data and routingpackets destined for that MG.

According to an exemplary embodiment, a neighbour groupdiscovery-procedure will be performed when an MGN receives a MobileGroup advertisement message. The MGN will read the message and checkwhether it originates in the local MG or if it comes from a differentMG. If the message originates in a different MG, the MGN will send aGroup Gateway Request (GGR) message to the MGL, indicating the ID of thenewly found MG. Depending on the rules in the policy engine, the MGL mayappoint the MGN to act as either a single MGG to the new MG, one of manyMGGs to the new MG, or the MGN will be denied status as MGG. If theinter-group route between two MGGs in different temporary Mobile Groupsbecomes invalid because of time out, each MGG will issue an Inter-groupRouting Error (IRE) message to its MGL, invalidating the gateway, andthe MGG loses its gateway status. returning to act as an MGN, unless itstill acts as MGG to some other Mobile Group. The MGN will, however,still listen for MG advertisement messages from other temporary MobileGroups, and may return to being an MGG if it receives an MGadvertisement message again.

A conventional MANET uses plain addressing, since any node may join anyMANET spontaneously, at any time. However, in a temporary Mobile Groupaccording to this invention, an MGN will periodically receive or forwardRREQs for destinations within the MG or outside of the MG, and the MGNmust be able to determine whether a routing message or data packet isdestined to an MGN in our MG, or to a completely different MG. Accordingto one exemplary embodiment of this invention, this is performed byinspection of the network number, or prefix part, of the destination IPaddress. The IP address of a node is e.g. reconfigured when an MGN isgranted membership in a temporary Mobile Group, followed by a reset ofwireless interfaces and a restart of the routing protocol. When a sourcenode originates a routing request, it will first check to see whetherthe destination node has an IP address with the same prefix as the MG,in which case the destination node is located in the same MG as thesource node, and the routing request constitutes a intra-group routingrequest to a local destination. If, on the other hand, the prefix of thedestination node differs from the prefix of the local MG, the routingrequest constitutes an inter-group routing request to a remotedestination. Each MGG will cache this routing request using a longtimer, and contact the MGL to negotiate in case this routing request isto be forwarded onto an inter-group link. The MGL, having valid routesto all MGNs and all MGGs, will now send an IG-RREQ-ALLOWED message toall MGG who shall forward this routing request onto their inter-grouplinks. The set of these nodes can be determined using the policy engineof the MGL. In order to propagate the RREQ onto inter-group links, eachpermitted MGG will transmit an IG-RREQ message to a peer MGG in anothergroup and wait for an IG-RREQ using a long time-out. The peer MGG willcheck if the incoming routing request is destined for the local MG ornot, and if it is destined to the local MG, the MGG will contact the MGLto check if it should propagate this as a standard RREQ into the localMG. If the IG-RREQ is destined for another network, the MGL in questionwill be able to forward this request to all other MGGs in the local MG,depending on the policy rules in the local MGL. In the inter-grouprouting reply, the first IG-RREQ that reaches its destination will bechosen as the Inter-group path to reply along. A list of traversed MGGwill be carried in the IG-RREQ and all subsequent IG-RREPs can travelbackwards along this suboptimal path to the source. Since the path issub-optimal (all traversed MGLs of the MG reside on the path betweensource and destination), local RREQs updating of the traversal routeswith more optimal routes will be initiated.

According to a further embodiment of this invention, the MGL is providedwith an IP address lease database, and a table binding a globally uniqueMGN ID to an IP address, in order to prevent the constantreconfiguration of node interfaces if a node temporarily looses groupmembership.

FIG. 3 schematically illustrates another Controlled Temporary MobileNetwork 3, comprising three temporary Mobile Groups 31, 32, 33,according to this invention. The first temporary Mobile Group, 31,comprises a Mobile Group Node MGN1, a Mobile Group Leader MGL1 and aMobile Group Gateway MGGA. The second temporary Mobile Group, 32,comprises a Mobile Group Node MGN2, a Mobile Group Leader MGL2 and twoMobile Group Gateways, MGGB and MGGC. The third temporary Mobile Group,33, comprises a Mobile Group Node MGN3, a Mobile Group Leader MGL3 and aMobile Group Gateway MGGD.

FIG. 4 is a signalling diagram illustrating an exemplary embodiment ofthe signalling during the setting up of a route between a first MGN,i.e. the MGN1 located in the first temporary Mobile Group 31, and asecond MGN, i.e. the MGN3, located in the third temporary Mobile Group,33, as illustrated in FIG. 3. FIG. 4 illustrates a routing requestIG-RREQ sent from MGN1 to MGN3, followed by the routing reply IG-RREPsent back from MGN3 to MGN1.

First, the source node MGN1 broadcasts a routing request in step 410,received by MGGA.

In step 415, MGGA contacts MGL1 regarding this routing request, and MGL1returns an IG-RREQ-ALLOWED to MGGA.

In step 420, MGGA creates and sends an IG-RREQ to the second MobileGroup 32, via MGGB.

In step 425, MGGB determines that the IG-RREQ is not destined for thisMobile Group by looking at the prefix, and forwards the IG-RREQ to MGL2.

In step 430, MGL2 forwards the IG-RREQ to MGGC. In step 435, MGGC passesthe IG-RREQ to the third Mobile Group 33, via MGGD.

In step 440, MGGD realizes that this IG-RREQ is destined for the thirdMobile Group, 33, and MGGD contacts MGL3, which consults its policyengine to determine whether this IG-RREQ is allowed in this MG.

In step 445, MGL3 responds that it is allowed.

In step 450, MGGD sends an RREQ to the third temporary Mobile Group 33,that is received by the destination node MGN3. Thereafter, MGN3 sends anIG-RREP to MGL3, in step 455.

In step 460, MGL3 forwards the IG-RREP to MGGD.

In step 465, MGGD forwards the IG-RREP to MGGC.

In step 470, MGGC forwards the IG-RREP to MGL2

In step 475, MGL2 forwards the IG-RREP to MGGB.

In step 480, MGGB issues an RREQ for MGGC, and receives an optimal routeto MGGA, and in step 485, the MGGB forwards the IG-RREP to MGGA.

In step 490, MGGA forwards the IG-RREP to MGL1, which, in turn, forwardsthe IG-RREP to MGN1 in step 495, thereby completing the set-up of theroute between MGN1 and MGN3.

FIG. 5 is a block diagram illustrating an embodiment of a communicationdevice 50, provided with a Controlled Temporary Mobile Networkfunctionality 52, which comprises an adaptable policy engine 54, inwhich an administrator is able to store selected policy rules, e.g.regarding secrecy requirements, in order to adapt the policy engine forthe management of a particular temporary, mobile group within a CTMNET.

By means of the solution according to this invention, a partitioned andcontrolled structure of temporary mobile groups can be created from alarge unstructured network of mobile nodes, while still handling thehigh probability of link breakage and a high level of mobility, which istypical for a wireless network. By means of the invention, any number ofmobile nodes may participate by the formation of several temporarymobile groups, the mobile groups capable of interfacing with othermobile groups, and to interact in a controlled manner by means of theadaptable policy engine.

The invention has been described with reference to specific exemplaryembodiments and figures only to illustrate the inventive concept, andthe invention is not limited to the disclosed embodiments. Instead, theinvention is intended to cover various modification within the scope ofthe appended claims.

1-16. (canceled)
 17. A communication device for controlling a temporaryMobile Group within a Controlled Temporary Mobile Network, the temporaryMobile Group comprising a plurality of Mobile Group Nodes, saidcommunication device comprising: an adaptable policy engine, which isconfigurable by an administrator to enable the device to act as a MobileGroup Node and Mobile Group Leader in the temporary Mobile Group; andmeans for controlling the joining of other Mobile Group Nodes in thetemporary Mobile Group according to the adaptable policy engine.
 18. Thecommunication device according to claim 17, further comprising means forcontrolling access to information resources in the temporary MobileGroup according to the adaptable policy engine.
 19. The communicationdevice according to claim 17, further comprising means for controllingmessage routing within the temporary Mobile Group between a source nodeand a destination node according to the adaptable policy engine.
 20. Thecommunication device according to claim 19, wherein the means forcontrolling message routing includes means for utilizing a prefix of anIP-address of the destination node.
 21. The communication deviceaccording claim 17, wherein the adaptable policy engine is configurableby the administrator to disable the device's capability to act as theMobile Group Leader.
 22. The communication device according to claim 17,wherein the adaptable policy engine is dynamically configurable byanother communication device acting as Mobile Group Leader to enable thecommunication device to act as a Mobile Group Gateway for communicatingwith another temporary Mobile Group.
 23. The communication deviceaccording to claim 17, wherein the adaptable policy engine includes atleast one policy rule that is settable by an administrator.
 24. Thecommunication device according to claim 23, wherein the adaptable policyengine includes at least one default policy rule.
 25. The communicationdevice according to claim 23, wherein when the communication device actsas a Mobile Group Node, the adaptable policy engine includes policyrules associated with the Mobile Group Node.
 26. A method in acommunication device for controlling a temporary Mobile Group within aControlled Temporary Mobile Network, the temporary Mobile Groupcomprising a plurality of Mobile Group Nodes, said method comprising thesteps of: configuring an adaptable policy engine in the communicationdevice to enable the device to act as a Mobile Group Leader in thetemporary Mobile Group; receiving a membership request message from aMobile Group Node requesting to join the temporary Mobile Group;consulting the adaptable policy engine to determine whether membershipin the temporary Mobile Group is allowed for the requesting Mobile GroupNode; and sending a reply to the requesting Mobile Group Node admittingthe requesting Mobile Group Node to the temporary Mobile Group if theadaptable policy engine indicates membership in the temporary MobileGroup is allowed for the requesting Mobile Group Node.
 27. The method ina communication device according to claim 26, wherein when thecommunication device acts as the Mobile Group Leader, the method furthercomprises controlling access to information resources within thetemporary Mobile Group by consulting the adaptable policy engine. 28.The method in a communication device according to claim 26, wherein whenthe communication device acts as the Mobile Group Leader, the methodfurther comprises appointing a Mobile Group Gateway within the temporaryMobile Group for communicating with another temporary Mobile Group, saidappointing step including: receiving a message from another Mobile GroupNode in the temporary Mobile Group requesting permission to communicatewith another temporary Mobile Group; consulting the adaptable policyengine to determine whether communication is allowed; and dynamicallyconfiguring the adaptable policy engine of the requesting Mobile GroupNode to act as a Mobile Group Gateway if the adaptable policy engineindicates communication is allowed.
 29. The method in a communicationdevice according to claim 28, further comprising routing a message froma source node within the temporary Mobile Group to a destination node inthe other temporary Mobile Group, said routing step including: receivinga routing request message from the source node via a Mobile GroupGateway of the temporary Mobile Group; consulting the adaptable policyengine to determine whether routing of the message is allowed; andsending a routing allowed message to the Mobile Group Gateway of thetemporary Mobile Group allowing forwarding of the routing requestmessage according to the adaptable policy engine to a Mobile GroupGateway of the other temporary Mobile Group.
 30. The method in acommunication device according to claim 26, wherein when thecommunication device acts as the Mobile Group Leader of a transitingtemporary Mobile Group, the method further comprises performing atransit routing of a message from a source node within another, first,temporary Mobile Group to a destination node within another, second,temporary Mobile Group, said step of performing a transit routingincluding: receiving a routing request message from a Mobile GroupGateway of the first temporary Mobile Group via a Mobile Group Gatewayof the transiting temporary Mobile Group; consulting the adaptablepolicy engine of the Mobile Group Leader; and sending a routing allowedmessage from the Mobile Group Leader in the transiting temporary MobileGroup to the Mobile Group Gateway of the transiting temporary MobileGroup allowing forwarding of the routing request message according tothe adaptable policy engine to a Mobile Group Gateway of the secondtemporary Mobile Group.
 31. The method in a communication deviceaccording to claim 30, wherein the routing utilizes a prefix of anIP-address of the destination node.
 32. The method in a communicationdevice according to claim 26, further comprising reconfiguring theadaptable policy engine in the communication device by an administratorto resign as the Mobile Group Leader.